I. Field of the Invention
The present invention relates to a pulsating vibration air generation means wherein accurate pulsating vibration air can be periodically and continuously generated by opening and closing a control opening of a valve by means of a cam mechanism while pressurized air or suction air is supplied from an inlet port to an outlet port.
II. Prior Art
A basic principle of such a pulsating vibration air generation means has been already proposed by the present inventor in Japanese Patent Application No.5-104028 (U.S. Pat. No. 5,458,458 issued on Oct. 17, 1995 and EPC Publication No. 0625659 published on Nov. 23, 1994).
FIGS. 17 and 18 show the pulsating vibration air generation means (a) proposed in the above-mentioned application. The construction and the operation are as follows. A pulsating air transmitting port (c) and two connecting ports for a blower (d, e) are provided around an external wall of a cylindrical casing (b). A valve plate (f) is rotated in the casing (b) accompanied with rotation of an axis (i) connected with a driving motor (not shown) with the inside of the casing (b) divided into two spaces (g, h) by the valve plate (f). When the valve plate (f) is continuously rotated in one direction while communicating the connecting ports (d, e) with a supply port (k) and a suction port (m) of a blower (j) respectively, positive pressure and negative pressure are generated alternately so that pulsating vibration air is emitted from the transmitting port (c).
However, there has been a room for improvement because highly pressurized air leaks between the valve plate (f) and the internal surface of the casing (b) when highly pressurized air is supplied in the above-mentioned pulsating air generation means (a) by means of an air source such as a compressor. Therefore, pulsating vibration air with high pressure and clear wave shape can't be generated.
Further, wave shape of pulsating air obtained by the pulsating air generation means (a) has been limited to the one which had previously set at the stage of designing and pulsating vibration air with an optional wave shape which has different rising or falling characteristics can't be obtained.